I. Field of the Invention
The present invention relates generally to a trailer landing gear construction and more particularly to an attachment and support means to support the vertical load between the landing gear housing and the landing gear foot.
II. Description of the Prior Art
The conventional landing gear assemblies comprise three discrete assemblies, namely a landing gear housing, an extension-retraction assembly (hereinafter for brevity, referred to as the extension assembly) and a landing gear foot. The landing gear housing comprises a generally vertical and cylindrical tube which is attached to the trailer body while the landing gear foot is adapted to engage the ground. The extension assembly, disposed intermediate and secured to the landing gear foot and the landing gear housing, may take any of several forms and functions to vertically extend or retract the landing gear foot relative to the landing gear housing.
In the previously known landing gear assemblies an axle carried at the lower depending end of the extension assembly is rotatably received within pair of registering apertures formed through the landing gear foot. Since the connection between the landing gear foot and the axle of the extension assembly must necessarily be able to withstand great vertical loads, it has been the practice with the previously known landing gear assemblies to weld a support plate over each aperture in the landing gear foot. The support plate, of course, includes an aperture which registers with the aperture in the landing gear foot and in essence serves to increase the axial length of the landing gear foot aperture thus increasing the support between the landing gear foot and the extension assembly. The major disadvantage of this previously known construction for the landing gear foot is that the weld between the support plate and the landing gear foot has been known to crack thereby reducing the effectiveness of the support plate and subjecting the landing gear foot to excessive vertical loads.
A further disadvantage of the previously known landing gear foot with support plates is that the support plates are relatively expensive to fabricate particularly in view of rising metal prices. In addition expensive welding equipment is required and high labor costs are incurred in securing the support plates to the landing gear foot.
Similarly, in order to attach the upper end of the extension assembly to the landing gear housing, a gear base plate is typically provided on the upper end of the extension assembly and is slidably received within the landing gear housing. The previously known gear base plates included a cylindrical portion having an outer diameter substantially the same as the inner diameter of the landing gear housing so that the cylindrical portion abuts the inside surface of the landing gear housing. In the previously known landing gear assemblies the cylindrical portion is then welded to the landing gear housing in order to attach the upper end of the extension assembly to the housing. Like the attachment between the extension assembly and the landing gear foot, the welds between the gear base plate and the housing are prone to crack thereby subjecting the attachment between the extension assembly and the housing to excessive stress. Also the welding operation between the gear base plate and the landing gear housing has proven to be unduly time consuming thus increasing the labor costs for the construction of the entire landing gear assembly.